The AG600, codenamed Kunlong, slides on the water surface of a reservoir near Zhanghe Airport in Jingmen, central China's Hubei Province, on Oct. 20, 2018.

China's self-developed amphibious aircraft AG600, codenamed Kunlong, is expected to take its maiden flight over the sea in the second half of 2020 in East China's Shandong Province, the Aviation Industry Corporation of China announced.

This would be major progress in the research of the airplane after it was flown over land in 2017 and on water in 2018.

The flight is to comprehensively test the aircraft's adaptability on the sea, such as the corrosiveness of sea water and the impact of wind and waves, Wang Yanan, an expert on aircrafts and chief editor of Aerospace Knowledge, told the Global Times on Sunday.

"If the test flight is successful, it means the aircraft can undertake more offshore missions," Wang said.

The research on the amphibious rescue airplanes depends on China's actual needs as it has a 32,000-kilometer-long coastline and large offshore waters, Wang said.

Wang expects that the aircraft may be one year before it is actually put into use in various scenarios.

"This aircraft is likely to be a platform. With this platform, it can be turned into a multi-purpose aircraft. For example it can be used in rescue on the sea, deliver materials to islands and reefs, emergency treatment and disaster relief as it can take off directly from rivers and lakes, and for sightseeing along coastal cities," he said.

So far, the AG600 has completed 308 hours of test flights in preparation for the sea flight. The city government of Qingdao, where the maiden flight will be carried out, is helping push security work such as maritime rescue, port dispatching and medical aid.

Similar in size to the Boeing 737, the AG600 can fight forest fires, undertake water rescues, monitor maritime environment and carry out patrol missions, according to media reports. It can rescue 50 people in distressat one time and carry out on-water rescue in complicated weather conditions.

A military expert told the Global Times earlier that the coronavirus outbreak does not have major impact on the project of the aircraft, and that a sea-test flight is a major milestone in the aircraft's development.